Field of the Invention
The invention relates to a technology for generating an image that shows a periphery of a vehicle.
Description of the Background Art
Conventionally, an image display system that generates an image showing the periphery of a vehicle such as a car, and displays the generated image on a display installed in a vehicle cabin is known. By use of such an image display system, a user (typically a driver) can check the periphery of the vehicle substantially in real time.
Another image display system proposed these days generates a composite image for display based on a plurality of shot images, showing the periphery of a vehicle viewed from a virtual viewpoint. Such an image display system is capable of generating, for example, an overview image that is a composite image showing the periphery of the vehicle viewed from the viewpoint set above the vehicle. The user can check the whole periphery of the vehicle by looking at such a composite image.
Such a composite image described above, showing the periphery of the vehicle viewed from the virtual viewpoint, is generated by use of the data of a plurality of shot images projected onto a virtual projection surface corresponding to the periphery of the vehicle. Such a projection surface is generally created in the shape of a horizontal plane along a horizontal direction. Another projection surface proposed these days is created in the shape where the area in the vicinity of a vehicle is a substantially horizontal plane and the slope of area farther away from the vehicle location is higher (like a bowl shape).
The area in the vicinity of the vehicle on either shape of the two projection surfaces described above for generation of a composite image is created in the shape of a substantially horizontal plane. Thus, the image of the object existing in the vicinity of the vehicle is projected onto the area of the substantially horizontal plane on the projection surface. As above, in the case where the image of the object is projected onto the area of the substantially horizontal plane, and where the object exists above a road in a distance, the image of the object is projected onto the location away from the vehicle location.
Therefore, when looking at the composite image generated by use of the data projected on the projection surface, the user may feel that the object existing actually in the vicinity of the vehicle is away from the vehicle. As a result, the user may drive the vehicle having misperception of the location relation between the vehicle and the object, since the object appears to be farther away from the vehicle than in reality for the user.